Free amine-containing polymeric dyes

ABSTRACT

Soluble polymeric colorants composed of free amine groups and chromophoric groups covalently bonded to an organic backbone are disclosed. The number of free amine groups is not less than one-half the number of chromophoric groups. The colorants are characterized by being free of sulfonate, phosphonate and carboxylate groups. The preparation and use of these colorants is also disclosed.

REFERENCE TO RELATED APPLICATION

This is a continuation of Application Ser. No. 832,254, filed Sept. 12,1977, and now abandoned which is a continuation-in-part of copendingU.S. patent application, Ser. No. 638,730, filed Dec. 8, 1975, now U.S.Pat. No. 4,051,138.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to polymeric coloring compositions. Moreparticularly, it relates to soluble polymeric colorants, characterizedas containing a substantial proportion of free amine groups.

2. Background Art

Polymeric colorants are composed of optically chromophoric groups boundto or into polymers. Such materials may be found in the prior art, forexample, in Horiguchi et al.'s U.S. Pat. No. 3,337,288, granted on Aug.22, 1967; in Wegman et al.'s U.S. Pat. No. 3,304,297, granted on Feb.14, 1967; in Japanese Published Patent Application 14,434, published in1966 and cited at 66 Chemical Abstracts 19843 j; in the article by Idaet al. appearing at pages 524-30 of volume 89(4) of YAKUGAKU ZASSHI; inKalopissis's U.S. Pat. No. 3,567,678, granted on Mar. 2, 1971; in Dawsonet al.'s U.S. Pat. No. 3,920,855, issued on Nov. 18, 1975; in thearticle by Dawson et al. appearing at pages 5996-6000 of volume 98:19 ofJACS, and in Otteson et al.'s South African Patent Number 76/7083, filedDec. 7, 1976. These and other references make it clear that in certainapplications polymeric dyes can offer real, functional advantages. Theirlarger molecular size reduces their diffusivity and increases theirfilm-forming properties. In food coloring applications polymeric colorscan offer yet another advantage which is pointed out in thealready-noted Ida et al., Dawson et al., and Otteson et al. references.If a polymeric color molecule has a large enough molecular weight andsize, it will be too large to be absorbed from the gastrointestinaltract when eaten with food. This means that the color will not pass intothe body, and any risk of systemic toxicity is essentially eliminated.

The polymeric colorant products disclosed in the cited Otteson andDawson references and also, in fact, the products claimed in thisapplication's parent may be classified as colorants that arewater-soluble as a result of the presence of anionic groups such assulfonates, sulfamates, phosphonates and the like, impartinghydrophilicity to the polymers. Such a method of solubilizing offers themajor advantage of imparting water-solubility in a wide range of aqueousenvironments.

The present invention concerns soluble polymeric colorants which haveamine solubilizing groups, but no significant number of anionicsolubilizing groups. These materials offer particular advantages. Theytend to be soluble in water at pHs of from about 2.0-4.0, but areinsoluble in water otherwise. Their amine groups can ionically bond tonegatively charged substrates. When applied to such a substrate, theyare relatively colorfast not only because of their being bonded to thesubstrate, but also because of their limited solubility.

STATEMENT OF THE INVENTION

A new and advantageous form of soluble polymeric coloring compositionhas now been found. These colorants contain a plurality (m) of opticallychromophoric groups covalently linked to carbon atoms of a hydrocarbonpolymer backbone. Also covalently attached to this backbone, but todifferent carbon atoms thereof, are a plurality (n) of independent freeamine groups selected from among the primary and secondary loweralkyl-amine groups. n and m are selected such that there is not lessthan one free alkylamine group for each two optically chromophoricgroups, and the colorant molecule has a molecular weight of not lessthan 2,000 daltons.

Colorants of this invention have the advantages of being soluble in pH2.0-4 aqueous media, but otherwise being relatively insoluble in waterand of being capable of ionically bonding to substrates such asproteinaceous fibers and the like, and thus bonding relatively quitefast to such substrates. These colorants are soluble in polar aproticsolvents and in wet water-miscible solvents such as alcohols. Because oftheir polymeric nature, they are of a molecular size which precludestheir absorption (passage) through the walls of the gastrointestinaltract or through other body surfaces so that they present minimal risksof systemic toxicity when consumed or used on the surface of the body.

DETAILED DESCRIPTION OF THE INVENTION

The polymeric colorants of this invention consist of organic polymericmolecules. These molecules have hydrocarbon polymer chain backbones.Free amine groups and separate optical chromophoric groups arechemically (covalently) attached to carbon atoms of the polymericbackbone.

The Free Amine Groups

The free amine groups employed in the present colorants are defined tobe primary or secondary lower alkyl amine groups. Primary amine groupsare preferred free amine groups. These groups are representedstructurally as ##STR1## groups wherein R₄ is hydrogen or a 1 to 4carbon saturated alkyl such as methyl, ethyl, propyl, isopropyl orbutyl, or a continuation thereof. Preferably, R₄ is hydrogen or methyl,and more preferably R₄ is hydrogen. These free amine groups may beattached directly to carbon atoms of the backbone, or they may beattached through an olefinically saturated lower hydrocarbon group(especially alkyl) which is itself pendant from the backbone. Thisconfiguration is shown as ##STR2## wherein R₄ is as previously definedand R₃ is selected from a carbon-nitrogen single bond, a 1 to 4 carbonsaturated alkylene bridge, such as methylene, ethylene, propylene orbutylene or a six carbon aromatic bridge--i.e., phenylene.

The Chromophoric Groups and Their Attachment

Also attached to the backbone are a plurality of optically chromophoricgroups. These groups, denominated "Chrom" in the structural formulae,are organic groups which present a visible color to the human eye.Suitable chromophores should contain no significant number of anionicgroups such as sulfonates, sulfamates, or phosphonates. These groups arecovalently bonded to the backbone in one of two configurations. First,they may be covalently bonded directly to backbone carbon atoms in a##STR3## configuration. Second, and this is a preferred arrangement,they may be linked through amine groups in an ##STR4## configuration,wherein R₃ and R₄ are as previously defined.

The Backbones

The backbones employed in the present colorants are hydrocarbons. Theyare olefinically saturated, that is they do not contain intentionallyincorporated olefinic unsaturation. Preferably, they are essentiallylinear, containing no appreciable long chain branching. The length ofthe backbone should be such as to assure a molecular weight of at least2000 Daltons to the final colorant molecule.

The Structure of The Colorants

The present colorants may be shown by following structural formula I.##STR5## wherein R₁ and R₁ ' independently are hydrogen or a lowersaturated alkyl of up to 4 carbon atoms, i.e., methyl, ethyl, propyl orbutyl; R₂ and R₂ ' independently are hydrogen, a lower saturated alkylof up to 4 carbon atoms or an aromatic hydrocarbon of about 6 carbonatoms, i.e., phenyl; R₃ is most commonly a simple carbon to nitrogensingle covalent bond, but also may be a 1 to 4 carbon atom lowersaturated alkylene bridge, or a 6 carbon atom aromatic (phenylene)bridge; R₄ is hydrogen or a lower saturated alkyl of 1 to 4 carbonatoms; R₅ is a carbon to carbon single bond, ethylene, a 1 to 4 carbonsaturated alkyl-substituted ethylene, a 6-8 carbon aromatic-substitutedethylene, or an oxyhydrocarbon or nitrohydrocarbon as hereinafter shown.Chrom is an optically chromophoric group and n, p, and m are numberssuch that n is at least 1/2 m and the sum of n+m+p is such as to assurea molecular weight of at least 2000 to the colorant molecule.

In the preferred embodiment wherein the chromophore units are attachedvia amine sites, the colorants have the "amine-site" structure shown inFormula II. ##STR6## wherein R₁, R₂, R₃, R₄, R₅, Chrom and n, m and pare as previously defined. Very preferably R₁ and R₂ are independentlyselected from hydrogen, ethyl or methyl, R₃ is a carbon to nitrogensingle bond, methylene or ethylene, R₄ is hydrogen, methyl or ethyl, R₅is a carbon to carbon single bond, ethylene, a 1 to 4 carbon saturatedalkyl substituted ethylene, and Chrom, n, m and p are as previouslydefined. Most preferably, R₁, R₂, and R₄ are hydrogen and R₃ is a carbonto nitrogen single bond and R₅ is a carbon to carbon single bond.

The polymeric colorants may be formed by several methods. For one, anethylenically unsaturated chromophore or precursor may be copolymerizedwith the free amine group containing monomer. More preferably, however,a chromophore is reacted with and bonded to a reactive site on aperformed amine site containing backbone. In the preferred embodiment,this reactive site is a portion of the total amine sites originallyincorporated into the backbone. The amine groups used as active sitesmay be incorporated into the chromophore, that is, they may participatein the color imparting structure of the chromophore or they may beindependent of the chromophore, serving only as a "color inert" point ofattachment. This "amine-site linked" embodiment is preferred because ofthe simplicity of production which it enables. A homopolymeric orcopolymeric backbone containing n+m amine groups is formed. Then, aportion (m) of these groups is used as chromophore attachment positions.

The following is a list of exemplary homopolymeric amine site-containingbackbones preferred for use in the colorants of this invention:poly(vinylamine), ##STR7## Preferred homopolymers includepoly(vinylamine), poly(N-methylvinylamine), andpoly(α-methylvinylamine).

The backbones may comprise added copolymeric units as well. These units,shown by R₅ in Formula I, need not be solely hydrocarbons but shouldonly add hydrocarbon to the structural chain of the backbone and shouldnot add anionic groups such as phosphonates, sulfonates or sulfamates.The added units include, for example, the hydrocarbons ##STR8## whereinR₆ is hydrogen, a 1 to 4 carbon alkyl or an aryl, alkaryl or aralkyl offrom 6 to 8 carbons; the oxyhydrocarbons ##STR9## and ##STR10## whereinR₇ is hydrogen, a 1 to 4 carbon alkyl, or a --O--CH₃ group; or anitrilohydrocarbon ##STR11## As is illustrated by these formulae, thesole contribution made to the backbone chain by these materials ishydrocarbon.

Size Of The Colorants

The length (or size) of the backbone chain and hence values of n, m andp are of importance. Clearly, since at least one chromophoric group isattached to the backbone through amine linkages and at least oneadditional cationic amine is present, the backbone must contain at leasttwo such amines. If one is to obtain most advantageous polymerproperties with the polymeric colors of this invention, n+m, that is thenumber of amino groups on a polymer chain, should be at least 20.However, if n+m is substantially greater than about 3000, say 5000 or10,000, generally the performance as colorants of the final polymersdecreases. Thus, a preferred size of backbone obtained when n+m isbetween 20 and 3000, more preferably when n is between 40 and 2000 andmost preferably when n is between 100 and 1500.

Formulae I and II show n free amine groups and m chromophore groups intheir structures. n and m are related numbers. 2n is greater than m.Preferably, n is greater than 1 times m, but not greater than about 6times m. The upper limit on n is dictated by practical considerations.If n is greater than 6m, the coloring power of the polymeric colorant isgenerally low since the colorant does not carry a sufficient number ofchromophores. More preferably, n is from 1.2 to 4 times m with a mostpreferred relationship being n equal to from 1.3 to 3.5 times m.

Formulae I and II also show p R₅ copolymerizate units. Thesecopolymerizate units are optional so p may equal 0. p may also be aslarge as about 2(n+m); preferably p is 0 or up to about 1(n+m); mostpreferably p is 0.

The backbones are generally prepared separately prior to chromophoreattachment. This may be done by free radically polymerizing olefinicallyunsaturated amine- or amine-precursor-substituted monomers. A number ofrepresentative backbone preparations are depicted herein in ExamplesI-VI. Alternative preparations are set forth at Kurtz and Disselnkotter,U.S. Pat. No. 3,424,791; Hanford and Stevenson, U.S. Pat. No. 2,276,840;Hanford and Stevenson, U.S. Pat. No. 2,231,905; Horwitz and Aschkenasy,Belgian 637,380; Hart, Makromol. Chem., 32, 51(1959); Hart, J. PolymerScience, 29, 629 (1958); Blomquist, et al., J. Am. Chem. Soc., 67, 1519(1965); Kurtz and Disselnkotter, Liebigs Ann. Chem., 764, 69 (1972);Bailey and Bird, J. Org. Chem., 23, 996 (1958); and Seki et al., Chem.Pharm. Bull., 20, 361 (1972); which disclosures are expresslyincorporated by reference into this patent application.

A very preferred embodiment of this invention comprises poly(vinylamine)homopolymer of molecular weight of 40,000 to 130,000 Daltons (i.e.,containing from about 1000 to 3000 amine groups) having from 20 to 67%of its amine groups substituted with chromophore units.

When experimental molecular weights are noted herein they have beenderived by gel permeation techniques. In the primary technique, asilanized porous glass support is used with 0.01 M LiBr in DMF eluent.Detection is by refractometer with standardization being based onpurchased polystyrene standards. Expressed in terms of molecular weight,examples of backbones meeting the general size criteria (n=20 to 3000)include poly(vinylamine) of molecular weight 860 to 129,000; poly(α, βor N-methylvinylamine) of molecular weight 1180 to 177,000 and poly(α orβ-butylvinylamine) of molecular weight 2020 to 303,000. In the sameterms, backbones meeting the most preferred size criteria (n=100 to1500) include poly(vinylamine) of molecular weight 4300 to 64,500 andpoly(α-methylvinylamine) of molecular weight 5900 to 88,500. Furtherpreferences in molecular size will be noted when the colorant productsare to be used as colorants for edible compositions. These will be setforth hereinafter.

More Detailed Description of Chromophores

The chromophoric groups employed in the present coloring compositionsare organic optical chromophores. These materials are defined to beorganic chemical groups which exhibit a visual color to the human eyewhen attached to a polymeric backbone. These chromophores can beselected from a wide range of classes of groups, including the azochromophores, anthraquinone chromophores, xanthene chromophores,triphenylmethane chromophores, indigoid chromophores and the like. Theseclasses of chromophores are merely representative--other similarmaterials also being usable. Among these chromophores, specialpreference is given to anthraquinone chromophores because of their greatstability under stressful conditions of heat and light and the widerange of colors which they permit. Among chromophores, those whichcontain no anionic groups such as sulfonates, sulfamates orphosphonates, and are themselves water-insoluble, generally achieve mostimproved usefulness when used in the present polymeric form. Achromophore is defined as being water-insoluble if its solubility inroom temperature water at neutral conditions (pH 7) is less than 500parts per million weight (basis water).

Preferred anthraquinone chromophores in their unattached (monomeric)state have a leaving group such as a --Cl, --Br, --I, --SO₃ Na,--N₂.sup.⊕ Cl.sup.⊖, or --NO₂ group attached to their aromatic ring.This permits the chromophore's facile use in the preferred colorantswherein some backbone amines are used to couple chromophores. In thistechnique copper is used to catalyze the leaving groups' displacement byamines. In many case, no catalyst is required to effect the desireddisplacement. Several classes of anthraquinone chromophores deservespecial mention:

Aminoanthraquinone chromophores of the structure of Formula III,##STR12## formed by coupling the monomer IIIA wherein R₁ is a hydrogenor a lower saturated alkyl of up to four carbon atoms, R₂ is hydrogen, alower saturated alkyl of up to four carbon atoms or an aryl or alkarylof from six to eight carbons and X is a leaving group. These are usefulto give the range of blue colorants listed in Table I.

                  TABLE I                                                         ______________________________________                                        COMPOUND                                                                      R.sub.1    R.sub.2          COLOR                                             ______________________________________                                        hydrogen   hydrogen         purplish blue                                     hydrogen   methyl           greenish blue                                     hydrogen   ethyl, propyl or butyl                                                                         greenish blue                                     hydrogen   aryl             navy blue                                         ______________________________________                                    

Anthrapyridones of the structure of Formula IV. ##STR13## formed bycoupling the corresponding monomer, wherein X is a leaving group, R₁ isa hydrogen, a lower saturated alkyl of 1 to 4 carbon atoms inclusive, analkaryl or an aryl grouping of from 6 to 8 carbons, R₂ is 1 to 4 carbonsaturated alkyl, a 1 to 4 carbon saturated alkoxy, and R₃ is a hydrogenor a 1-4 carbon lower saturated alkyl. These chromophores are rich redsand violet-reds. Preferred among the anthrapyridones are these accordingto Formula IV wherein R₁, R₂, and R₃ are shown in Table II.

                  TABLE II                                                        ______________________________________                                        R.sub.1    R.sub.2        R.sub.3                                             ______________________________________                                        hydrogen   2-5 carbon alkyl                                                                             1-4 carbon alkyl                                    hydrogen   methyl         methyl                                              hydrogen   methoxy        1-4 carbon alkyl                                    hydrogen   methoxy        methyl                                              hydrogen   ethoxy         1-4 carbon alkyl                                    hydrogen   ethoxy         methyl                                              methyl     methyl         hydrogen                                            methyl     phenyl         hydrogen                                            methyl     ethoxy         hydrogen                                            ______________________________________                                    

Anthrapyridines of the structure of Formula V: ##STR14## which areformed by coupling the corresponding monomeric chromophore ##STR15##wherein X is a leaving group, R₁ is a 2 to 5 carbon lower saturatedcarbalkoxy, a 2 to 5 carbon lower saturated alkyl, an aroyl, an aryl orsubstituted (halo, nitro, alkoxy, or alkyl) aryl grouping of about 6 to9 carbons, R₂ is hydrogen or a 1 to 4 carbon lower alkyl, and R₃ is a 1to 3 carbon lower saturated alkyl, a 1 to 3 carbon lower saturatedalkoxy, an alkaryloxy (i.e., benzyloxy) of about 7 to 9 carbons, or anaryl grouping of about 6 carbons. These colorants range in hues fromyellows to reds to brown. Preferred among the anthrapyridines are thoseaccording to Formula V where R₁, R₂, and R₃ are shown in Table III.

                  TABLE III                                                       ______________________________________                                        R.sub.1         R.sub.2     R.sub.3                                           ______________________________________                                        carbethoxy      methyl      methyl                                            carbomethoxy    methyl      methyl                                            carbethoxy      methyl      methoxy                                           carbethoxy      methyl      ethoxy                                            carbethoxy      methyl      benzyloxy                                         phenyl          methyl      methoxy                                           phenyl          methyl      ethoxy                                            phenyl          methyl      benzyloxy                                         ______________________________________                                    

Pyridinoanthrone dyes of the structure of Formula VI: ##STR16## may alsobe used. These are formed by coupling the corresponding monomericchromophore wherein R₁ is hydrogen or a 1 to 4 carbon saturated alkyland R₂ is a hydrogen or a 1 to 4 carbon alkyl.

Anthrapyrimidines of the structure of Formula VII: ##STR17## formed bycoupling the monomeric chromophores of the formula wherein R₁ ishydrogen, a 6 carbon aryl, a 1 to 4 carbon saturated alkyl or a halogenas described in U.S. Pat. No. 1,947,855 which deals with monomericcolorants. R₂ is a hydrogen or 1 to 4 carbon alkyl. These materials arereds and yellows.

Anthrapyrimidones of the structure of Formula VIII: ##STR18## formed bycoupling the monomeric chromophores. These materials are violets. R is ahydrogen or 1 to 4 carbon alkyl. Substitution of 4 position by aminogroup gives violet dye (U.S. Pat. No. 1,004,107).

The anthraquinones of the structure of Formula IX: ##STR19## formed bycoupling the monomeric chromophores shown in Formula IX A. Thesematerials are reds.

Anthrapyridones of the structure of Formula X: ##STR20## formed bycoupling the monomeric chromophores of X A, wherein R₁ is hydrogen,methyl, or aryl, R₂ is hydrogen or 1 to 4 carbon lower alkyl and R₃ ishydrogen, a halogen (i.e., Br or Cl), cyano (i.e., --CN), NO₂ or a loweralkyl of 1 to 4 carbon atoms.

Among the azo colorants, those having monomeric forms with a sulfonylchloride comprise one preferred group since they may be easily attachedto the amine backbone via the well known Schotten-Baumann reaction.Exemplary chromophores of this class and chlorosulfonyl precursorsinclude the first four materials shown in Table IV. Also listed in TableIV are several nonazo chromophores which are attached via theSchotten-Baumann reaction.

                                      TABLE IV                                    __________________________________________________________________________    Chromophore              Precursor                                            __________________________________________________________________________     ##STR21##                                                                                              ##STR22##                                            ##STR23##                                                                                              ##STR24##                                            ##STR25##                                                                                              ##STR26##                                            ##STR27##                                                                                              ##STR28##                                            ##STR29##                                                                                              ##STR30##                                           R.sub.1 = H, or 1 to 4 C alkyl                                                R.sub.2 = H, or 1 to 4 C alkyl                                                R.sub.3 = 1 to 4 C alkyl or alkoxy                                            R.sub.4 = H, or 1 to 4 C alkyl or alkoxy                                       ##STR31##                                                                                              ##STR32##                                            ##STR33##                                                                                              ##STR34##                                            ##STR35##                                                                                              ##STR36##                                            ##STR37##                                                                                              ##STR38##                                            ##STR39##                                                                                              ##STR40##                                            ##STR41##                                                                                              ##STR42##                                           R.sub.1 = CH.sub.3 O , CH.sub.3 S, or Br                                       ##STR43##                                                                                              ##STR44##                                           R.sub.1 = H, CO.sub.21 to 4 carbon alkyl, CO1 to 4 carbon alkyl, or           phenyl                                                                        R.sub.2 = H or 1-4 carbon alkyl                                                ##STR45##                                                                     ##STR46##                                                                                              ##STR47##                                           Red as shown in Brit. Patent 525,091 (1941)                                    ##STR48##                                                                    __________________________________________________________________________

Preparation Of The Compounds

Conceptually, the compounds of this invention can be prepared by thefollowing basic routes:

1. A polymerizable unsaturated amine or amine precursor can becopolymerized with a polymerizable unsaturated chromophore generallyunder free radical conditions. As a species of this process, anunsaturated amine or amine precursor can be copolymerized with anunsaturated amine-containing chromophore.

2. A polymerizable unsaturated amine or amine precursor can becopolymerized with a polymerizable unsaturated chromophore precursoralso generally under free radical conditions to yield a polymer productwhich can be further processed to yield the desired aminecontaining-polymeric colorant.

3. A preformed backbone can be treated to attach amines and then toattach chromophores.

4. A preformed amine-containing backbone can be treated to attachchromophores to a portion of the amine groups.

Of these routes, the last is the most preferred. The first two routessuffer the disadvantage of not permitting the close control of molecularsize which is achieved when a separate purified backbone is used. Thethird route conceptually may be used, but it generally is easier toincorporate amines directly when the backbone is being formed (as inroute 4) rather than adding them to the backbone.

When this last route is followed, this first step involves obtaining anamine group-containing polymer backbone. In the case wherepoly(vinylamine) is the backbone, a full disclosure of one route to thepolymer is given in U.S. Pat. No. 4,018,826, issued Apr. 19, 1977, byGless et al., which application is herein incorporated by reference, andwhich route is exemplified herein as Example 1. In the case where thebackbone is a poly(N-alkyl-vinylamine) such a material can be preparedby first reacting the corresponding N-alkylaminoethanol with an excess(preferably from 2 to 3 equivalents) of an acid anhydride, preferablyacetic anhydride, at an elevated temperature, especially 75°-140° C., toyield in 5-60 minutes the bis-acetylated product which in the case whereacetic anhydride is used has the formula ##STR49## R is lower N-alkylsuch as methyl and "Ac" are acetyl groups resulting from added aceticanhydride. The bis-acetylated product is pyrolyzed in vapor phase at350°-600° C. to yield N-alkylvinylacetamide. The N-alkylvinylacetamidemay be purified, by distillation or crystallization, and thenpolymerized in liquid phase in the presence of a suitable free radicalinitiator such as benzoyl hydroperoxide, other organic peroxides orother initiators such as AIBN or the like. This polymerization isgenerally carried out at a temperature of from 40°-100° C. and at acatalyst level of from 0.5-10% mole. It is generally carried out in asuitable organic liquid solvent, especially a lower alkanol, such asmethanol, ethanol, or isopropanol. The resulting poly(N-alkylvinylamide)is then hydrolyzed by contact with an excess of a mineral acid, such assulfuric, hydrochloric, perchloric or the like. This reaction is slow,requiring temperatures of at least 80° C. and as high as 175° C. andtimes of from 20-100 hours to go to completion. The hydrolysis productis the desired poly(N-alkylvinylamine) as the corresponding acid salt.

Once the backbone of choice is at hand, the next step in the preparationof the present compounds is to attach the chromophores. As pointed outin the description of suitable chromophores, there are several routeswhich find excellent application with certain classes of chromophores.For example, in the case of anthraquinone chromophores, it is possibleto effect facile attachment by employing an anthraquinone bearing aleaving group attached to its aromatic ring. This leaving group isreadily displaced by the backbone amine, generally in the presence of acopper catalyst, such as copper metal, cuprous oxide, copper I salts(cuprous chloride, etc.), copper II salts (cupric acetate, etc.) andcomplexes of copper and copper oxides or salts with a carbon carrier.One peculiarity of this reaction is the general need to employ awater-miscible cosolvent, such as methanol, ethanol, isopropanol,β-methoxy ethanol, diethylene glycol, ethylene glycol,N,N-dimethylformamide, dimethylsulfoxide, pyridine, tetrahydrofuran,N-methylpyrdlidone, with an about 5:1 to about 1:5 proportion of water.

This reaction is generally carried out at an elevated temperature, suchas from about 80° C. to about 130° C., with the aqueous solvent refluxtemperature often being most convenient.

When an azo chromophore is used, it is useful to employ a chromophorebearing a sulfonyl halide group or a methyl halide group, especially amethyl chloride or bromide group. These functionalities react with theamine backbone in the presence of base at pH 10-11 to form the desiredcouple. The former reaction is often referred to as the Schotten-Baumannreaction and goes smoothly at temperatures of from 0° to 60° C. andrequires from about 2 to 12 hours to complete. In the case of azocompounds, it should be remembered that the polymer backbone with itsamine groups could interfere with an attempt to diazotize an attachedazo dye precursor. Thus, it is best when azo colors are involved toattach a diazotized (pre-coupled) color unit, rather than anundiazotized azo color precursor.

Use of Colorants

The colorants of this invention are soluble in water at pH 2.0-4.0, butrelatively insoluble in water at other pHs. Solubility and insolubilitymay be quantified as follows: A material is insoluble if a saturatedsolution contains less than 500 ppm of the material. If the solutioncontains more, the material is soluble. This solubility at certain pHsoffers advantages. The colorants may be applied in solution form to asubstrate at pH 2.0-4.0. Then, the pH may be raised or lowered out ofthis soluble range. This causes the colorants to deposit on thesubstrate in a relatively permanent form. The colorants of thisinvention are positively charged. This means that they have specialaffinity for negatively charged substrates. This can have practicalsignificance in the coloring of proteinaceous substrates such as wool orhair where the colorants achieve fast and relatively permanentcoloration. In the coloring of hair or wool, a pH 2.0-4.0 solution ofthe colorant is applied and then the substrate is rinsed with neutralwater. As the pH goes from 4.0 to 7, the colorant precipitates and isdeposited on the substrate. Similarly, the colors can be applied to thesubstrate from an organic-water solution and rinsed with water toachieve fast and relatively permanent coloration. Suitable organic-watermixtures are water with from about 25% w to about 400% w (basis water)and preferably 50% to 300 by weight on the same basis of lower alkanol(of 1 to 4 carbons) such as methanol, ethanol, isopropanol or butanol,lower (2 to 3 carbon) alkandiols such as ethylene glycol or propyleneglycol, and lower (3 to 5 carbon) alkanones such as acetone,methylethylketone or diethylketone.

The colorants also find use in other media such as in pigments, paintsand the like. In another use, these colorants are admixed with ediblematerials, such as foods, beverages, medicines and the like. In this useit is most useful that the colorants be sized such that their molecularweight is not less than about 1500, preferably from 2000 to 200,000,most preferably from 5,000 to 150,000. A colorant of this molecularweight has a molecular size which is too large to permit its absorptionthrough the walls of the gastrointestinal tract and thus any risk ofsystemic toxicity arising from absorption of colorant from thegastrointestinal tract is eliminated. The colorants, because of theircarbon-carbon backbone, and stable chromophore linkages, are essentiallyfree of degradation at the conditions of passage through thegastrointestinal tract. This nonabsorbability feature may also be ofadvantage when coloring containers and wrappings for edibles, as anycolor which might migrate into the edible would be nonabsorbable.

In nonedible applications, such as in hair dyes, paints, dyes, etc., thecolors of this invention may be used alone or may be admixed with othercolorants in amounts of from about 20 ppm to 10% by weight basiscolorant solutions.

In applications with edible materials, the colorants are added in aneffective coloring amount, say from about 10 ppm to about 1% by weight(preferably from 10 ppm to 1000 ppm) to foods such as gelatin desserts,dispersed in cereals, added to fruits and other canned foods, tobeverages such as carbonated beverages, for example orange, grape andcherry soda, wines and the like; and added to medicines such as coughelixers, cough drops and diverse other usually colored medicaments forman or beast alike. These applications involve the art known proceduresof dispersing, dissolving or otherwise spreading the colorant upon orthrough the object to be colored.

The invention will be further described by references to the followingexamples. These are intended to provide an understanding of specificembodiments of the invention and are not to be construed as limiting theinvention's scope.

EXAMPLE I

Preparation of poly(vinylamine) backbone:

A. Preparation of Vinylacetamide

To 9304 g of acetamide (technical) in a 12 liter reaction flask wasadded 62.2 ml of 6 M aqueous sulfuric acid followed immediately by 661 gof acetaldehyde (99+%). This mixture was stirred and heated until theinternal temperature reached 78° C. (11 minutes) at which point theclear solution spontaneously crystallized, causing a temperature rise to95° C. The reaction product, ethylidene-bis-acetamide, was notseparated. Heating and stirring were continued for another 5 minutes toa temperature of 107° C. and a mixture of 150 g calcium carbonate(precipitated chalk) and 150 g of Celite® diatomaceous earth powder wasadded. A first distillate fraction of water and acetamide was removed.The remaining material was transferred to a 22 liter flask and crackedat 35 mm Hg and 185° C. A fraction made up of vinylacetamide andacetamide, was taken overhead and pooled with seven other previouslyprepared batches. This pooled material was analyzed by NMR and found tocontain 5.77 kg of vinylacetamide and 2.45 kg of acetamide.

B. Polymerization of Vinylacetamide

The vinylacetamide-acetamide mixture of Part A was mixed with 4.1 l ofisopropanol and chilled overnight. Crystallized acetamide was removed byfiltration. The filtrate plus rinses were diluted to a total isopropanolvolume of 30.58 l. This solution was placed in a 50 l flask,deoxygenated and heated to 88° C. Then a solution of 233 g of AIBNpolymerization catalyst in 830 ml of acetone was added and the mixturewas stirred at temperature for about 4 hours to complete polymerization.The resulting thick solution was stripped of solvent to a volume of 15.3liters and then poured into 95 l of stirred acetone. The polymer formeda precipitate which was recovered by filtration, rinsed with acetone,and dried at 50° C. in a vacuum oven. The final product was 5 kg ofpoly(vinylacetamide) of a molecular weight of 30,000.

C. Hydrolysis of Poly(vinylacetamide) to Poly(vinylamine hydrochloride)

The poly(vinylacetamide) obtained in Part B (4.97 kg) was dissolved in5.85 l of water with heating in a 50 l flask. Concentrated hydrochloricacid (5.85 l) was added and the resulting solution was stirred andheated at a gentle reflux (97°-106° C.) for 23 hours. A precipitateformed and was redissolved by addition of 1,170 ml of water. Reflux wascontinued and over the next 17 hours, 1,000 ml of water was added inseveral portions to maintain solubility of the polymer. After a total of40 hours at reflux, the polymer was precipitated by the addition of 5.85l of concentrated hydrochloric acid. A thick polymeric gum was isolatedby decantation and dried under vacuum at 50°-100° C. with occasionalpulverization for 56 hours to give 3.1 kg of poly(vinylaminehydrochloride) as a granular solid.

EXAMPLE II

Preparation of poly(N-methylvinylamine):

A. Formation of bis-acetylate

The preparation of poly(N-methylvinylamine) was begun by adding 250 g ofN-methylaminoethanol to 691 g (2.20 equivalents) of acetic anhydride at115°-120° C. The reaction was very exothermic (cooling required) and wascomplete by the time the addition was concluded. The bis-acetylatedproduct, ##STR50## was isolated by vacuum distillation (bp 95°-98°/0.1mm) as a colorless oil in 93% yield.

B. Pyrolyses of bis-acetylate

The bis-acetylated product of Step A was pyrolyzed by passing 642 g ofthis material at a rate of 1.17 g/min through a Pyrex® helices-packedquartz tube (3.5 cm diameter, 40 cm length) maintained at 480°. A 400ml/min argon stream was employed. The crude pyrolysate was a dark orangeoil weighing 629 g. The crude mixture containing the desiredN-methylvinylacetamide was distilled (72° C./20 mm) to afford 119 g(30%) of purified N-methylvinylacetamide.

C. Polymerization

Polymerization of 75 g of purified N-methylvinylacetamide was carriedout in 150 ml of methanol at 70° C. in the presence of 4 mol % of AIBN.The polymerization was complete within 12 hours and afforded 72 g (96%yield) of poly(N-methylvinylacetamide).

D. Hydrolysis

The polymeric amide of Step C was hydrolysed with 6 N HCl at 125° toyield poly(N-methylvinylamine) as the hydrochloride. This material had amolecular weight of about 20,000 as determined by gel permeationchromatography comparisons to standards. The hydrolysis was monitored byNMR and required roughly 40 hours to go to completion. The product wasisolated in essentially quantitative yield by precipitation of thepartially evaporated reaction mixture from isopropanol.

EXAMPLES III AND IV

Preparation of high and low molecular weight poly(vinylaminehydrochloride):

The polymerization of vinylacetamide set forth in Step B of Example Iwas repeated twice on a smaller scale and varying reaction conditions tochange the product molecular weight.

In Example III, the relative amount of AIBN polymerization catalyst wasreduced by a factor of four, the reaction temperature was lowered to 63°C. and the reaction time was increased to 87 hours. The product wasrecovered as in Example I, Step B and found to have a molecular weightof 110,000. This material was hydrolyzed to poly(vinylamine)hydrochloride by the method of Example I, Step C.

In Example IV, the relative volume of isopropanol solvent employed wasdoubled. This reduced the average molecular weight of thepoly(vinylacetamide) product to 20,000. The poly(vinylacetamide) washydrolyzed to poly(vinylamine) in accordance with the process of ExampleI, Step C.

EXAMPLE V

Preparation of poly(α-methylvinylamine):

A. Preparation of 2-Amino,2-Cyano-Propane

85.1 g (1 mole) of acetone cyanohydrin is placed in a 2 l pressurevessel and the temperature is raised to 75° C. The pressure is raised to25 psi with NH₃ gas and is maintained there until the pressure no longerdrops (approximately 45 minutes). The crude product is then distilled toafford 46.5 g (0.55 mole, 55%) of product as a colorless oil, bp58°-60°/20 mm.

B. Preparation of 2-Acetamido-2-Cyano-Propane

46.0 g (0.55 mole) of the aminonitrile is added to 67 g (1.20 equiv.) ofAc₂ O with stirring at 80°. After 10 minutes the crude product is vacuumdistilled to afford 55.9 g of a yellow solid, bp 115°/0.20 mm.

Recrystallization from benzene affords 48.3 g (0.38 mole, 70%) of creamcolored needles.

C. Preparation of Isopropenyl Acetamide

Pyrolysis of the acetamido nitrile is carried out by passing 27.6 g(0.22 mmole) through a 4 mm Pyrex® helix packed quartz column maintainedat 600°. The column employed is 3.5 cm in diameter and 40 cm in length.The addition is carried out under a vacuum of 15 mm and the HCNgenerated is collected in a liquid N₂ trap. The product is 17.5 g ofdark yellow solid. Distillation affords 10.4 g (0.10 mole, 48%) ofproduct as a pale yellow crystalline solid, bp 72°-76°/0.20 mm.

D. Preparation of Polyisopropenyl Acetamide

5.0 g (43.9 mmole) of 89% pure isopropenyl acetamide is refluxed for 60hours under Ar in 15 ml of MeOH containing 144 mg of AlBN. The productis isolated by precipitation from acetone to afford 1.39 g (28%) of awhite powder. The molecular weight is 2,000.

E. Preparation of Polyisopropenyl Amine

300 mg (3.03 mmole) of the above material is refluxed for 24 hours in 20ml of 6 N HCl under Ar. The reaction solvent is removed to afford 0.42 gof product. Analysis indicated it to be 73% deacetylated.

EXAMPLE VI

Preparation of Poly(N-butyl vinylamine):

A. Formation of bis-acetate

117 g (1 mole) of N-n-butylaminoethanol is treated with 225 g (2.2 mole)of Ac₂ O at 100° for 4 hours. The bis-acetate is obtained by vacuumdistillation in about 82% yield.

B. Pyrolysis of bis-acetate

The bis-acetate product of Step A is pyrolyzed by passing 100.5 g (0.5mole) of this material at a rate of 1.25 g/min through a Pyrex®helices-packed quartz tube (3.5 cm×40 cm) maintained at 495°. A 400ml/min Ar stream is employed. The crude pyrolysate is a brownish-orangeoil weighing 87.3 g. The crude mixture containing the desiredN-n-butylvinylacetamide is distilled (96°/20 mm) to afford 30.3 g (43%,0.22 mole) of product.

C. Polymerization

A sample of 25.0 g (0.18 mole) of purified vinylacetamide from Step Babove is polymerized in 60 ml of MeOH at reflux in the presence of 4mole % AlBN. The polymerization is complete within 18 hours and afforded23 g (92%) of poly(N-n-butylvinylacetamide). The product is isolated byprecipitation from ether and the molecular weight is determined to beabout 38,000.

D. Hydrolysis

The polymeric amide of Step C is hydrolyzed with 10 parts by weight of 6N HCl at 125°. The yield of poly(N-n-butylvinylacetamine) as thehydrochloride salt is quantitative. The hydrolysis, which is monitoredby NMR, requires about 60 hours to reach completion. The product isisolated by precipitation of the partially evaporated reaction mixturefrom isopropanol.

EXAMPLE VII

Preparation of a Red Colorant:

A. Preparation of 1-nitro-2-methylanthraquinone

To a 1 liter flask was added 100 g (0.45 mole) of 2-methylanthraquinoneand 500 ml of 96% H₂ SO₄. The mixture was stirred until it was entirelyhomogeneous and then cooled to 0° C. The addition of 50.5 g (0.50 mole)of KNO₃ was then carried out in ten portions in such a way that thetemperature did not rise above 5° C. This required two hours. A yellowproduct precipitated out after roughly half the KNO₃ had been added.

The yellow slurry was then stirred at 0° C. for 20 hours and poured into12 l of ice/H₂ O with vigorous stirring. Stirring was stopped, theprecipitate was allowed to settle, and the liquid was removed. Theprecipitate was washed with water until the pH of the wash water was pH4-5.

An aqueous slurry of the precipitate (2.5 liters in volume) was placedin a 5 liter flask. 100 g of Na₂ SO₃ were added and the mixture washeated and stirred at 95° C. for three hours. The slurry was filtered.The solids were washed with boiling H₂ O and sucked dry. The product wasshown to be 1-nitro-2-methylanthraquinone.

B. Preparation of 1-amino-2-methylanthraquinone

The wet filter cake of 1-nitro-2-methylanthraquinone (0.45 mole) wasplaced in a 5 l flask. To the flask was added 420 g (1.75 mole) of Na₂S.9H₂ O dissolved in 2.5 l of H₂ O and the slurry was heated and thenstirred at 95°-99° C. for 2 hours. The reaction mixture was filtered andthe orangish-red solid 1-amino-2-methylanthraquinone product was washedwith hot H₂ O until the filtrate was clear and dried in vacuo at 70° C.

C. Preparation of 1-amino-2-methyl-4-bromoanthraquinone

Into a 250 ml flask was added 10 g (42.2 mmole) of1-amino-2-methylanthraquinone of Part B and 150 ml of glacial aceticacid. The mixture was heated to 35° C. and 8.44 g (52.8 mmole) ofbromine was added in one portion. After stirring for 20 hours at 35° C.,TLC (CHCl₃ on SiO₂) showed 10-20% of residual starting material stillremaining.

An additional 1.69 g (0.25 equivalent) of Br₂ was added and thetemperature was raised to 50° C. for 4 hours. TLC at this time indicatedthat the reaction was essentially complete.

The reaction mixture was cooled to room temperature and filtered. Thesolid product was washed with acetic acid (50 ml) and H₂ O (100 ml).

The wet filter cake was added to 500 ml of hot (80° C.) H₂ O containing25 g of NaHSO₃ and stirred for 30 minutes at this temperature. The redsolid 1-amino-2-methyl-4-bromoanthraquinone was recovered, washed anddried.

D. Preparation of 3'-carbethoxy-2-methyl-4-bromo-1,9-anthrapyridone

With magnetic stirring, two mmoles (630 mg) of the bromoanthraquinoneprepared in Part C were treated with 4.02 g (26 mmole) of diethylmalonate and 9 mg of Na₂ CO₃ for two hours at 180°-190° C. Volatileswere removed with an argon stream. After cooling, the product wasfiltered and the residue was washed with alcohol, hot water, and alcoholagain and stirred overnight with 100 ml of toluene. After filtration anddrying, the yield was 0.70 g (85%) of solid,3'-carbethoxy-2-methyl-4-bromo-1,9-anthrapyridone, i.e. ##STR51## Thismaterial was not substantially soluble in water. Its solubility wasestimated to be less than 50 ppm (basis water).

E. Preparation of a Polymeric Colorant

A 200-ml, one-neck flask was charged with 0.64 g (8 mmol) of thepoly(vinylamine hydrochloride) prepared in Example I, 3.4 g (32 mmol) ofNa₂ CO₃, and 75 ml of H₂ O. The mixture was stirred until a homogeneoussolution (pH 10.7) was obtained and 25 ml of pyridine was added. Then,1.64 g (4 mmol) of 3'-carbethoxy-2-methyl-4-bromoanthrapyridone,prepared in Step D, was added along with 143 mg (1 mmol) of red Cu₂ Oand the mixture was lowered into a bath pre-heated to 120° C. andstirred vigorously at reflux for 30 minutes.

The reaction mixture was filtered, while still boiling hot, through asintered glass filter and the small amount of residue was washed with100 ml of H₂ O-pyridine (3:1). A clear solution (200 ml, pH 10.8) of thefollowing red polymeric dye in 3:1 water-pyridine was obtained.##STR52## The solution was divided into two equal portions with oneportion being purified as is described in Step G below, and the otherhalf being purified as is described in Step H.

F. Preparation Of Nonsolubilized Colorant By Dialysis

One-half (100 ml) of the solution obtained in Step E was placed in aregenerated cellulose dialysis bag (average pore radius 24 A, estimatedmolecular weight cutoff 2×10⁴) and dialyzed against 4 liters of 25%aqueous pyridine for 72 hours. Following this, dialysis was carried outagainst 25% aqueous pyridine that was 0.5% by weight NaCl until thepolymer completely precipitated (˜10 days). Dialysis was then carriedout against dilute saline solution (72 hours) and finally against pureH₂ O (24 hours). After centrifugation (8000 rpm for one hour) anddrying, there was obtained 700 mg of polymeric dye as a fine red powder.This polymeric dye was soluble in water at pHs of from about 2.0 toabout 4.0, but otherwise was not substantially water-soluble. n and mwere calculated as being equal, i.e., n=m based on feed ratios. Byelemental analysis, m was seen to equal 0.95n.

G. Purification Of Nonsolubilized Colorant By Ultrafiltration

100 ml of the solution obtained in Step F was ultrafiltered with anAmicon Model 202 stirred cell (Amicon Corp., Lexington, Mass.) employinga 62 mm diameter PM 10 membrane (molecular weight cutoff 1×10⁴). Thedevice was operated at 40 psi Ar pressure. Ultrafiltration was carriedout with 2.9 liters (29 diavolumes) of 15% aqueous pyridine made up to0.02 N in NaOH (pH 12). After ultrafiltration the solution wasprecipitated onto 50 g of Celite® which was in 1 liter of rapidlystirred isopropyl alcohol containing 5 ml of acetic acid. The Celite wasfiltered, washed with isopropyl alcohol (2×200 ml) and dried.

The dye was extracted from the Celite by a two-fold treatment (stirred30 minutes) with 200 ml of H₂ O containing approximately 10 ml of 12 NHCl (pH 2.0). Filtration of the Celite followed by partial evaporationof the solution (pH maintained at 2-3 by the addition of HCl asnecessary) and lyophilization provided 540 mg of polymeric dye.

EXAMPLE VIII

Preparation of a red colorant:

A. Coupling Of Chromophores

To a solution of 1.87 g (70 mmol-1 equivalent) of thepoly(N-methylvinylamine hydrochloride) prepared in Example II, inaqueous ethylene glycol (2:1 glycol/water) containing 4 equivalents ofNa₂ CO₃, was added 1/2 an equivalent of the3'-carbethoxy-2-methyl-4-bromo-1,9-anthrapyridone prepared in Step D ofExample VII and 0.2 g of red Cu₂ O. The reaction was completed in 1.5-2hrs at 110° C. The catalyst and other solid contaminants were removed byfiltration to yield a solution of the coupled colorant ##STR53##

B. Workup

The dye was purified in a manner identical to that of Example VII, PartH. The yield of red polymeric product was 3.67 g. Elemental analysisshowed m=0.43 and n=0.57.

EXAMPLE IX

A. Preparation of 3'-acetyl-2-methyl-4-bromo-1,9-anthrapyridone

A 100 ml flask was charged with 3.6 g (10 mmole) of the1-amino-2-methyl-4-bromoanthraquinone of Part C of Example VII, 10 ml(10.2 g, 78.5 mmole) of ethyl acetoacetate and 0.033 g (0.31 mmole) ofsodium carbonate. The mixture was heated under a slow argon flow in a180°-190° C. oil bath with stirring. Lower boiling materials (H₂ O,EtOH, etc.) were distilled off as they were produced. After heating for1.5 hours, a thin layer chromatogram (silica gel, ethyl acetate)indicated the reaction was complete. The reaction mixture was cooled andfiltered. The residue was washed with ethanol, hot water, and ethanol;then the residue was stirred with boiling toluene for 5 minutes andfiltered. This process was repeated four times and the final residue wasdried in a 44° C. vacuum oven overnight to yield 3.32 g (87% yield) of3'-acetyl-2-methyl-4-bromo-1,9-anthrapyridone, i.e., ##STR54##

B. Coupling Of Dye Chromophore To A Polymer

A 250-ml, one-neck flask was charged with 0.64 g (8 mmol) of thepoly(vinylamine hydrochloride) of Example III, 3.4 g (32 mmol) of Na₂CO₃, and 75 ml of H₂ O. The mixture was stirred until a homogeneoussolution (pH 10.7) was obtained. The solution was then treated with 25ml of pyridine, 1.53 g (4 mmol) of3'-acetyl-2-methyl-4-bromoanthrapyridone prepared in Step A of thisExample, 143 mg (1 mmol) of red Cu₂ O and lowered into a bath preheatedto 120° C.

After refluxing 30 minutes, the reaction mixture was filtered whilestill boiling hot and the trace of residue washed with 100 ml of 25%aqueous pyridine. This afforded a bright red solution of polymeric dyeof the formula ##STR55##

C. Purification

The 200 ml of polymeric dye solution (pH 11.5) were purified byultrafiltering (9.0 liters of pH 12 15% aqueous pyridine), precipitatingonto Celite, washing, and re-extracting into pH 2H₂ O as described inExample VII, Step G. After lyophilization, there was obtained 480 mg ofproduct. Elemental analysis showed m=0.33 and n=0.67.

EXAMPLE X

A. Preparation of N-Acetyl-1-Methylamino-4-Bromoanthraquinone

A 250 ml flask equipped with a mechanical stirrer was charged with 30 g(95 mmole) of 1-methylamino-4-bromoanthraquinone (purchased fromSandoz), 19.5 g (191 mmole) of acetic anhydride, and 0.23 g of 96% H₂SO₄. The sludgelike mixture was heated and stirred at 110° for 30minutes. The reaction mixture was cooled to 0° and 50 ml of H₂ O wasadded. After stirring 1/2 hour, 55 ml of 30% NaOH was added and theentire mixture was then transferred to a pressure reactor for thefollowing reaction. A TLC (EtOAc) showed only a single product in thereaction.

B. Preparation of 1'-Methyl-4-Bromoanthrapyridone

The acetyl anthraquinone from Part A was placed in a pressure vessel andheated and stirred at 120° for 2 hours. The reaction mixture was cooled,filtered, and washed with H₂ O. After oven drying, the brown solid wasdissolved in 200 g of 96% H₂ SO₄ and reprecipitated by the addition of40 ml of H₂ O. The solid was filtered and washed with 25 g of 78% H₂SO₄. The filter cake was then stirred with 800 ml of H₂ O, filtered,washed, and dried in vacuo. The solid then obtained was twicerecrystallized from trichloroethane to afford 8.5 g of pureanthrapyridone.

C. Polymer Attachment Step

A 250 ml round bottomed flask was charged with 480 mg (6.0 mmole) ofpoly(vinylamine) of Example I, 2.54 g (24.0 mmole) of Na₂ CO₃, and 36 mlof H₂ O. The mixture was stirred until solution was complete and 72 mlof ethylene glycol was added. Then, 510 mg (1.50 mmole, 0.25equivalents) of 1'-methyl-4-bromoanthrapyridone was added along with 50mg of Cu₂ O. The reaction mixture was then placed in a pre-heated oilbath, refluxed for ten minutes, and rapidly filtered. The red polymericdye obtained in the filtrate is of the following composition. ##STR56##

D. Workup

Purification was carried out by bag dialysis as described in ExampleVII, Step G. The yield of product was 0.57 g. Elemental analysis showedm=0.23 and n=0.77.

EXAMPLE XI

Preparation of a blue polymeric dye:

A. Coupling Of Dye To Polymer

A 250-ml, 3-neck flask, equipped with overhead stirrer, refluxcondenser, Ar bubbler, and thermometer, was charged with 1.19 g (15mmol) of poly(vinylamine hydrochloride) prepared in Example I and 50 mlof H₂ O. The mixture was stirred until homogeneous and then treated with0.60 g (15 mmol) of NaOH and 1.6 g (15 mmol) of Na₂ CO₃. The mixture wasstirred under Ar until homogeneous (pH 12.6) and then treated with 0.476g (1.5 mmol) of 1-methylamino-4-bromoanthraquinone, ##STR57## preparedaccording to C. V. Wilson, Org. Syn., 29, 68 (1949), and 10 mg of Cu₂Cl₂ as a slurry in 30 ml of pyridine. The reaction mixture wasthoroughly deoxygenated with Ar and immersed in a preheated oil bath andrefluxed under Ar.

The following treatments were made to the refluxing reaction mixture atthe total elapsed times (based on attainment of reflux) indicated:

(a) 60 min, 1.50 mmol bromoanthraquinone, 20 ml pyridine;

(b) 120 min., 1.50 mmol bromoanthraquinone, 5 mg Cu₂ Cl₂, 10 mlpyridine;

(c) 180 min., 1.50 mmol bromoanthraquinone, 10 ml pyridine, 0.25 ml (3mmol) of 12 N NaOH;

(d) 240 min., 1.50 mmol bromoanthraquinone, 5 mg Cu₂ Cl₂, 15 mlpyrydine;

(e) 300 min., 0.75 ml (3 mmol) of 12 N NaOH.

A total of 7.5 mmol of anthraquinone was added and the total volume ofthe reaction mixture was 135 ml (pyridine: H₂ O/85:50). After 360minutes, TLC (CHCl₃ on SiO₂) showed that no starting material remained.The polymeric blue colorant was filtered while still boiling not througha sintered glass filter and purified as described in Step B.

B. Purification

Without allowing the solution to cool, the dye was precipitated asrapidly as possible into one liter of rapidly stirred ice-cold acetonecontaining 20 g of Celite. After stirring ten minutes, the dyed Celitewas filtered and washed with acetone (4×300 ml). The filtrates containedmonomeric species and inorganic salts.

The blue polymeric dye was extracted from the Celite by eightconsecutive treatments with one liter of dilute aqueous HCl (pH 2.5).After concentration (HCl added as needed to maintain the pH at 3.0), thesolution was freeze-dried to provide 2.06 g of cationic polymeric bluedye. Elemental analysis of the material showed that m=0.48 and n=0.52such that the product was ##STR58##

EXAMPLE XII

Preparation of a purple polymeric colorant:

A. Preparation of Chromophore ##STR59## was vacuum sublimed. A 12.1 gportion (52.7 mmoles) was placed in a flask and dissolved in 50 ml ofacetic acid with warming. 9.3 g of neat bromine was added along with 65ml of additional acetic acid and 30 ml of nitrobenzene. The mixture wasstirred and gradually heated--finally being maintained at 90° C. for 12hours. The reaction mixture has become homogeneously yellow. The mixturewas cooled and poured into a liter of water and 500 ml ofdichloromethane to yield two phases. The color went to the organic phasewhich was isolated, dried with Na₂ SO₄, filtered and evaporated to yielda solid chromophore which upon analysis was found to be: ##STR60##

B. Coupling

358 mg (3.81 mmole, 1 equivalent) of the poly(N-methylvinylaminehydrochloride) of Example II and 10 ml of water and 25 ml of ethyleneglycol are placed in a 100 ml flask. 1.62 g (15.2 mmole) of sodiumcarbonate, 0.5 g (0.42 equivalents) of the chromophore of Part A, and 50mg of a cupric acetate catalyst are added and the mixture is heated to110° C. and there maintained for 2-3 hours. Solids are removed byfiltration to yield a clear ethylene glycol/water solution of the purplecolorant ##STR61##

C. Workup

The product is isolated by precipitation onto Celite and extraction intodilute acid as described in Example XI, Step B. The yield of purplepolymer is 0.45 g after lyophilization.

EXAMPLE XIII

Preparation of a polymeric orange colorant:

A. Preparation of Chromophore

Using the general method disclosed in Patki et al., Indian Journal ofTechnology, Vol. 12 (1974) p 540-545, 31.6 g (100 mmole) of theanthraquinone product of Example VII, Step C, is suspended in 100 ml ofwater. Sodium hydroxide (15 g in 60 ml of water) is added with stirringfollowed by 70 g (1.2 mole) of acetone. The mixture is refluxed for 20hours. A TLC test indicates that the anthraquinone and acetone havereacted to completion. The mixture is cooled, neutralized withhydrochloric acid, and filtered to recover the yellow precipitate of2,4-dimethyl-6-bromopyridinanthrone ##STR62## which is washed with waterand dried.

B. Coupling

A 100 ml flask is charged with 0.64 g (8 mmole) of the poly(vinylaminehydrochloride) of Example III, 3.4 g (32 mmole) of Na₂ CO₃, 32 ml ofwater, and 65 ml of ethylene glycol. Then 1.02 g (3.0 mmole) of theproduct of Step A, along with a catalyst consisting of 0.25 g of finelypowdered cuprous oxide is added and the mixture is stirred at 100°-110°C. for 30 minutes. The reaction mixture is filtered to remove solids andyield an orange glycol/water solution of the polymeric colorant:##STR63##

C. Workup

The product was purified by bag dialysis vs. aqueous pyridine asdescribed in Example VII, Step G. The yield of polymer as a yellowpowder, after filtration and drying, was 0.85 g.

EXAMPLE XIV A. Chromophore preparation

1-amino-4-bromoanthraquinone, acetoacetic acid ethyl ester and alkanesulfonic acid catalyst are reacted in accordance with the teachings ofExample 1 of U.S. Pat. No. 2,759,940 issued Aug. 21, 1956 to Bucheler etal., (which patent is herein expressly incorporated by reference) toyield the yellow chromophore ##STR64##

B. Coupling of Chromophores to Backbone

0.37 g (4 mmole) of the poly(isopropenylamine) hydrochloride prepared inExample V is dissolved in 48 ml of 2:1 ethylene glycol/water along with1.70 g of Na₂ CO₃. Then, 0.79 g (2 mmole) of the chromophore of Step Ais added along with 0.3 g of cupric acetate monohydrate catalyst. Themixture is heated at 100° C. for 40 minutes.

The reaction mixture is filtered to remove solid residues and yield asolution of the yellow polymeric colorant ##STR65##

C. Workup

The product was precipitated by addition to one liter of rapidly stirredacetone containing 20 g of Celite. Thorough extraction of the celitewith dilute HCl (pH 3.0), followed by evaporation and freeze-drying,afforded 0.75 g of polymeric yellow colorant.

EXAMPLE XV

A. Preparation of Chromophore

4.4 g (10 mmole) of D&C Orange #4, ##STR66## is reacted overnight atroom temperature with an excess of acetic anhydride in pyridine toacetylate the naphthyl hydroxyl group. The acetylated product isrecovered, and added to a solution of one equivalent thionyl chloride in100 ml of benzene containing a catalytic amount of DMF. After stirringfor 2 hours at room temperature, the bright orange chlorosulfonylderivative, ##STR67## is recovered.

B. Coupling of Chromophore to Backbone

7.0 g of the poly(vinylamine hydrochloride) prepared in Example IV isadded to a 2000 ml flask, 700 ml of water and 350 ml of tetrahydrofuranare added and the pH is raised from 2.5 to 9.5 by addition of 2.5 NNaOH.

Next 13.7 g (0.4 equivalents, based on total amine polymer) of thechromophore of Part A is slowly added at room temperature whilemaintaining the pH at 9.0-9.5 by NaOH addition. Additional THF and NaOHare added and the pH is maintained at 9.5-10.5. A final stirring iscarried out at pH 12.5-13.0 to complete hydrolysis of the acetyl group.The product is not isolated, but is used immediately for Step C.

C. Workup

All THF was removed by evaporation at reduced pressure to provide a pH13.0 solution of the following anionic dye. ##STR68## Ultrafiltration ofthis solution was then carried out with 15% aqueous pyridine made up to0.02 N in NaOH (pH 12.0). Roughly 10 diavolumes were required to removethe monomeric impurities. The solution was then precipitated onto 200 gof Celite which was in 10 liters of rapidly stirred acetone containing100 ml of acetic acid. The Celite was filtered, washed with acetone (4×1liter), and dried.

The dye was extracted from the Celite by five one-hour treatments with 2liters of dilute HCl (pH 2.0). Evaporation of the solution (pHmaintained at 2-3 by the addition of HCl as necessary) andlyophilization provided 15.5 g of brilliant orange polymeric dye.##STR69##

EXAMPLE XVI

A. Preparation of Chromophore

1. 3'-Carbethoxy-2-Bromo-4-p-Toluidinoanthrapyridone

31.4 g (77.1 mmoles) of 1-amino-2-bromo-4-p-toluidinoanthraquinone(Benzenoid Organics Inc.), 250 ml of diethylmalonate, and 0.63 g ofsodium acetate were heated at 180°-185° under an argon stream for 105minutes. During this period the reaction mixture turned from deep blueto purplish red. The reaction mixture was cooled to 45° and the excessdiethylmalonate was removed in vacuo (0.25 mm). The product was dried at80°/0.1 mm for 18 hours and had the following structure: ##STR70##

2. Potassium 3'-Carbethoxy-4-p-Toluidinoanthrapyridone-2-Sulfonate

The crude product from the above reaction (38.8 g, 77.1 mmoles) wasrefluxed with 40.0 g of K₂ SO₃ in H₂ O/φOH (3:7). The course of thereaction was followed by TLC (5% MeOH/CHCl₃ elution on silica gel).After 48 hours, the reaction was judged complete. The phenol was removedwith steam, at which point the product precipitated. The royal purpleproduct was filtered and dried in vacuo to afford 39.7 g of monomericdye of the following structure: ##STR71##

3. 3'-Carbethoxy-4-p-Toluidinoanthrapyridone-2-sulfonyl Chloride

3.90 g (7.2 mmole) of the above anthrapyridone sulfonate, 83.5 g (0.71mole) of thionyl chloride, and 25 drops of DMF were stirred at roomtemperature for 7 days in 100 ml of 1,1,2,2-tetrachloroethane. Theexcess reagent and solvent were removed by vacuum distillation and thepurple residue was dissolved in methylene chloride and filtered toremove KCl. Removal of the solvent and drying in vacuo afforded aquantitative yield (3.76 g) of sulfonyl chloride. ##STR72##

B. Chromophore Attachment (Schotten-Bauman Reaction)

318 mg (4.0 mmoles) of poly(vinylamine) hydrochloride (prepared inExample I) was dissolved in 15 ml of H₂ O and the pH was raised to 10.0by the addition of 10% NaOH solution. To the solution was added 349 mg(0.66 mmole) of the anthrapyridone sulfonyl chloride of Part A and 5 mlof ethylene glycol. These additions were repeated twice more over aperiod of 7.5 hours as the pH was maintained at 9.5-10.5 by the additionof NaOH, as necessary.

C. Workup

The product of this reaction is isolated as follows. ##STR73## Thealkaline aqueous glycol mixture was diluted to a volume of 100 ml with15% aqueous pyridine made up to 0.02 N with NaOH (pH 12.0) andultrafiltered with an Amicon Model 202 stirred cell utilizing a PM 10membrane (molecular weight cutoff 1×10⁴). After the ultrafiltration hadbeen carried to 10 diavolumes (1.0 liter) with this pyridine solution,the deep purple mixture was precipitated into one liter of rapidlystirred isopropyl alcohol containing 50 g of Celite and 5 ml of aceticacid.

The dye was extracted from the Celite by two 30 minute treatments with250 ml of H₂ O made to pH 2.0 with HCl. This afforded, afterlyophilization, 514 mg of royal purple polymer shown by elementalanalysis to have m=0.46 and n=0.54.

EXAMPLE XVII

A. Preparation of Chromophore

1. 3'-Carbethoxy-2-methyl-4-anilinoanthrapyridone

4.12 g (10 mmole) of 3'-carbethoxy-2-methyl-4-bromoanthrapyridone(purchased from Sandoz Colors and Chemicals) was stirred under an inertatmosphere with 25 ml of aniline in a bath maintained at 145°-150°.After 2.5 hrs, TLC (EtOAc on silica gel) indicated the completedisappearance of starting material with the formation of a sole product.Removal of the excess aniline by vacuum distillation followed by dryingin vacuo (100°/0.1 mm) afforded a quantitative yield of product (4.24g).

2. Chlorosulfonation

4.00 g (9.43 mmole) of 3'-carbethoxy-2-methyl-4-anilinoanthrapyridonewas dispersed in 25 ml of CHCl₃ and the mixture was cooled to 0°. To themixture was added dropwise over a period of 1 hr 5 equivalents (4.10 g)of chlorosulfonic acid. After stirring at 0° for an additional 1 hr, thereaction mixture was filtered and the product was washed well with CHCl₃(0°) and then dried in vacuo to afford 4.66 g (8.91 mmoles) of sulfonylchloride as a violet-red crystalline solid. Elemental analysis confirmsthe following structure: ##STR74##

B. Coupling

523 mg (1.0 mmole) of the above sulfonyl chloride was treated with 3.0mmoles (238.5 mmoles) of poly(vinylamine) in 40 ml of THF-H₂ O (1:3) atroom temperature and pH 10.5-11.0. This afforded a red polymeric dyewith poor water solubility of the following structure: ##STR75##

C. Workup

The THF was removed from the bright red dye solution by rotaryevaporation and the mixture was then diluted to a volume of 100 ml with15% aqueous pyridine made up to 0.02 N with NaOH. The mixture wasultrafiltered to a total of 15 diavolumes (1.5 liters) of this pyridinesolution and then precipitated onto 65 g of Celite in 1.5 liters ofrapidly stirred isopropyl alcohol containing 25 ml of acetic acid.

Extraction of the dye from the Celite was carried out by two 30 minutetreatments with 500 ml of H₂ O made to pH 3.0 with HCl. This afforded,after evaporation and freeze-drying, 643 mg of bright red polymeric dyeshown by elemental analysis to have m=0.30 and n=0.70.

EXAMPLES XVIII AND XIX

The preparation of Example VIII is repeated twice varying the backboneemployed. In Example XIX, 1.1 equivalent of poly(N-butylvinylamine), asprepared in Example VI, is employed as backbone. In Example XX,poly(α-methylvinylamine), as prepared in Example X, is employed asbackbone.

EXAMPLE XX

A. Preparation of3'-carboethoxy-2'-methyl-2-methyl-4-bromo-1,9-anthrapyridine

Following the teachings of Bucheler and Peter in U.S. Patent No.2,759,940 (cited previously in Example XIV, Step A), 15.8 g (50 mmol) of1-amino-2-methyl-4-bromoanthraquinone (Example 7, Step C) were heatedfor three hours at 135°-140° C. with 178.5 g (1.37 mol) of acetoaceticester and 1.0 ml of methane sulfonic acid. During the course of thereaction, volatiles were removed with a slow stream of Ar. Aftercooling, the reaction mixture was diluted with ethanol (100 ml),filtered, and the residue washed with ethanol to provide 17.9 g of thefollowing bromoanthrapyridine as a dark brown powder. ##STR76##

B. Preparation of an Orange Dye

A 250-ml, three-neck flask, equipped with overhead stirrer, refluxcondenser, Ar bubbler, and thermometer, was charged with 1.19 g (15.0mmol) of poly(vinylamine hydrochloride) prepared in Example I, 0.60 g(15 mmol) of NaOH, 1.60 g (15 mmol) of Na₂ CO₃, and 50 ml of H₂ O. Themixture was stirred until a homogeneous solution was obtained (pH 12.6),at which point the solution was treated with 615 mg (1.50 mmol) of theanthrapyridine prepared in Part A, 10 mg of Cu₂ Cl₂, and 30 ml ofpyridine. The reaction mixture was lowered into a pre-heated bath andstirred at reflux under Ar.

The following treatments were made to the reaction at the timesindicated:

(a) 60 minutes, 1.5 mmol bromoanthrapyridine, 20 ml pyridine;

(b) 120 minutes, 1.5 mmol bromoanthrapyridine, 5 mg Cu₂ Cl₂, 10 mlpyridine, 0.25 ml (3 mmol) of 12 N NaOH;

(c) 210 minutes, 1.5 mmol bromoanthrapyridine, 10 ml pyridine;

(d) 300 minutes, 1.5 mmol bromoanthrapyridine, 5 mg Cu₂ Cl₂, 20 mlpyridine, 0.25 ml (3 mmol) of 12 N NaOH.

After 390 minutes, the reaction mixture was filtered through a sinteredfunnel while still hot and immediately diluted with 160 ml of boilingpyridine.

C. Workup

The 300 ml of deep orange solution (pyridine: H₂ O, 5:1, pH 12.9) wasadded as rapidly as possible (no cooling) to 2.5 liters of rapidlystirred ice-cold acetone containing 50 g of Celite. After stirring 15minutes, the celite was filtered and washed with acetone (4×500 ml). Thefiltrate was examined by TLC and was shown to contain principallymonomeric species.

The orange polymeric dye was extracted from the Celite by eightconsecutive treatments with one liter of dilute aqueous HCl (pH 3.4).This afforded, after lyophilization, 2.34 g of cationic orange dye.Elemental analysis showed that m=0.42 and n=0.58. ##STR77##

EXAMPLE XXI

A. Preparation of a Blue Dye

A 250-ml, 3-neck flask, equipped with overhead stirrer, refluxcondenser, Ar bubbler, and thermometer, was charged with 1.19 g (15mmol) of poly(vinylamine hydrochloride) prepared in Example I, 0.6 g (15mmol) of NaOH, 1.6 g (15 mmol) of Na₂ CO₃, and 50 ml of H₂ O. Thesolution was stirred until homogeneous (pH 12.5) and then treated with476 mg (1.5 mmol) of 1-amino-2-methyl-4-bromoanthraquinone (Example VII,Step C), 10 mg of Cu₂ Cl₂, and 30 ml of pyridine. The mixture waslowered into a preheated bath (125° C.) and stirred at reflux under Ar.

The following treatments were made to the reaction mixture at the timesindicated:

(a) 60 minutes, 1.5 mmol bromoanthraquinone, 20 ml pyridine;

(b) 120 minutes, 1.5 mmol bromoanthraquinone, 5 mg Cu₂ Cl₂, 10 mlpyridine;

(c) 210 minutes, 1.5 mmol bromoanthraquinone, 10 ml pyridine, 0.25 ml (3mmol) of 12 N NaOH;

(d) 300 minutes, 1.5 mmol bromoanthraquinone, 5 mg Cu₂ Cl₂, 20 mlpyridine, 0.25 ml (3 mmol) of 12 N NaOH.

A TLC (CHCl₃ on SiO₂) after 390 minutes showed that almost no4-bromoanthraquinone remained. The mixture was filtered while stillboiling hot through a fritted filter and diluted with 160 ml of boilingpyridine.

B. Purification

Without allowing the dye solution to cool, the deep blue solution wasprecipitated into 2.5 liters of rapidly stirred ice-cold acetonecontaining 50 g of celite. After stirring for 15 minutes, the celite wasfiltered and washed thoroughly with acetone (4×500 ml). The purplishfiltrate contained (TLC analysis) primarily1-amino-2-methyl-4-hydroxyanthraquinone and a trace of1-amino-2-methyl-4-bromoanthraquinone which remained unreacted.

The blue polymeric dye was extracted from the celite by ten consecutive30 minute treatments with one liter of dilute aqueous HCl (pH 2.5).Lyophilization provided 1.98 g of cationic blue polymeric dye. Elementalanalysis showed than m=0.44 and n=0.56. ##STR78##

EXAMPLE XXII

A. Preparation of 3'-phenyl-2-methyl-4-bromo-1,9-anthrapyridone

A 250-ml flask, equipped with overhead stirrer, condenser, and Ar inletwas charged with 15.8 g (50 mmol) of1-amino-2-methyl-4-bromoanthraquinone (Example VII, Step C) and 120 mlof toluene. The mixture was treated with phenylacetyl chloride (8.5 g,55 mmol) and heated to reflux. After 3.5 hours, the mixture was cooledto 80° and filtered. The filtrate was evaporated to 30 ml and cooled.The deposited dark yellow crystals were filtered, washed withdiethylether, and dried to afford 12.5 g of N-phenylacetylanthraquinone.

This material (4.56 g, 10.5 mmol) was placed in a 100-ml, 3-neck flaskequipped with condenser, overhead stirrer, thermowell, and Ar inlet.After 30 ml of 2-methoxyethanol were added, the contents were heated to122° C. and 0.45 g (8 mmol) of KOH in 0.6 ml of H₂ O was added dropwiseover 60 seconds. After stirring for one hour at 120° C., the mixture wascooled to 5° C. and the solid obtained (1.71 g) was filtered.Concentration of the mother liquor and recrystallization of the residuefrom acetic acid (170 ml) afforded an additional 2.30 g of product. Thetotal yield of anthrapyridone was 4.01 g. ##STR79##

B. Preparation of a Red Polymeric Dye

A 200-ml, one-neck flask was charged with 0.64 g (8 mmol) ofpoly(vinylamine hydrochloride) prepared in Example I, 3.4 g (32 mmol) ofNa₂ CO₃, and 75 ml of H₂ O. The mixture was stirred until a homogeneoussolution (pH 10.7) was obtained. 25 ml of pyridine and 1.67 g (4 mmol)of 3'-phenyl-2-methyl-4-bromoanthrapyridone prepared in Step A wereadded along with 143 mg (1 mmol) of red Cu₂ O and the mixture waslowered into a bath preheated to 120° C. and stirred vigorously atreflux for 180 minutes. The reaction mixture was filtered while stillboiling hot and diluted with 100 ml of 15% aqueous pyridine made up to0.02 N in NaOH.

C. Purification

The red polymeric dye solution (200 ml, pH 12.0) obtained in Step B##STR80## was ultrafiltered with an Amicon Model 202 stirred cell inconjunction with a PM 10 membrane (molecular weight cutoff 1×10⁴).Ultrafiltration was carried out with 4.0 liters (20 diavolumes) of 15%aqueous pyridine made up to 0.02 N with NaOH. The red dye solution wasthen precipitated onto 100 g of celite which was in 2 liters of rapidlystirred isopropyl alcohol containing 10 ml of acetic acid. The celitewas filtered, washed with isopropyl alcohol (2×400 ml), and dried.

The dye was extracted from the celite by two treatments with 500 ml ofdilute aqueous HCl (pH 2.0). This afforded, after freeze-drying, 1.23 gof red polymeric dye. Elemental analysis showed m=0.48 and n=0.52.

EXAMPLE XXIII

A. Preparation of3'-carbethoxy-2'-methoxy-2-methyl-4-bromo-1,9-anthrapyridine

A 500-ml, 3-neck flask, equipped with overhead stirrer, thermometer, andAr bubbler, was charged with 4.12 g (10 mmol) of3'-carbethoxy-2-methyl-4-bromoanthrapyridone prepared in Example VII,Step D, and 200 ml of dry N,N-dimethylformamide. Stirring was begun andthe mixture was heated to 40° and thoroughly deaerated with Ar. Themixture was then treated with 1.38 g (10 mmol) of anhydrous K₂ CO₃ and6.30 g (50 mmol) of dimethyl sulfate and stirring was continued at thistemperature under Ar.

The reaction was followed by TLC (EtOAc on SiO₂) which showed the cleanformation of a single product. After 72 hours the reaction mixture waspoured into 1.4 liters of well stirred water and, after stirring fiveminutes, the product was allowed to settle. Decantation, followed byfiltration and water washing, provided 3.76 g (8.8 mmol) ofmethoxyanthrapyridine. The structure of the product was determined bynuclear magnetic resonance spectroscopy, infrared spectroscopy,ultraviolet spectroscopy, and elemental analysis. ##STR81##

B. Preparation of an Orange Polymeric Dye

A 250-ml, 3-neck flask, equipped with overhead stirrer, refluxcondenser, Ar bubbler, and thermometer, was charged with 1.19 g (15mmol) of poly(vinylamine hydrochloride) prepared in Example I, 0.6 g (15mmol) of NaOH, 1.6 g (15 mmol) of Na₂ CO₃, and 50 ml of H₂ O. Themixture was stirred until a homogeneous solution was obtained (pH 12.6),at which point the solution was treated with 639 mg (1.50 mmol) of themethoxyanthrapyridine prepared in Part A, 10 mg of Cu₂ Cl₂, and 30 ml ofpyridine. The mixture was lowered into a pre-heated bath (125°) andstirred at reflux under Ar.

The following treatments were made to the reaction at the timesindicated:

(a) 60 minutes, 1.5 mmol methoxyanthrapyridine, 20 ml pyridine;

(b) 120 min, 1.5 mmol methoxyanthrapyridine, 5 mg Cu₂ Cl₂, 10 mlpyridine, 0.25 ml (3 mmol) of 12 N NaOH;

(c) 210 minutes, 1.5 mmol methoxyanthrapyridine, 10 ml pyridine;

(d) 300 minutes, 1.5 mmol methoxyanthrapyridine, 5 mg Cu₂ Cl₂, 20 mlpyridine, 0.25 ml (3 mmol) of 12 N NaOH.

After 390 minutes the reaction mixture was filtered through a frittedfunnel while still boiling hot and immediately diluted with 160 ml ofboiling pyridine.

C. Workup

The 300 ml of deep orange solution (pyridine:H₂ O, 5:1, pH 13.0) wasadded as rapidly as possible (no cooling) to 2.5 liters of rapidlystirred ice-cold acetone containing 50 g of celite. After stirring 15minutes, the celite was filtered and washed with acetone (4×500 ml). Thefiltrate was examined by TLC which showed only monomeric materials.

The orange polymeric dye was extracted from the celite by eightconsecutive treatments with one liter of dilute aqueous HCl (pH 3.5).This afforded 2.58 g of cationic orange dye. Elemental analysis showedthat m=0.44 and n=0.56. ##STR82##

EXAMPLE XXIV

The red colorant of Example VII is employed as a dye for wool and hair.A solution of the colorant is prepared by dissolving 0.1 g of theproduct of Example VII in 50 ml of pH 3 water. Small samples of bleachedhuman hair and white wool yarn are immersed in the colorant solution for90 seconds at room temperature. Times from 10 seconds to 10 minutes maybe used as well. The samples of hair and wool are removed, pressedbetween two filter papers, rinsed briefly in deionized water, pressed toremove rinse water, and allowed to dry at ambient conditions. The hairand the wool are colored red. A portion of each colored material istested for color-fastness. When placed in water, there is a very slight,almost imperceptible, coloring of the test water, indicating that thepolymeric colorant has formed a fast bond to the substrate.

If this experiment is repeated using other colorants prepared in theexamples, similar results are achieved.

A plurality of colorants may be present in the dyeing solution. Suitabledyeing solutions are aqueous solutions which have acidic pH's,preferably from about pH 2 to about pH 5, and more preferably from pH2.5 to pH 4.0. Also suitable are solutions having up to 80% ofwater-miscible organic liquids in these, preferably oxyhydrocarbonorganics selected from among 1 to 4 carbon alkanols, 2 to 4 carbonalkandiols and 3 to 5 carbon alkanones, particularly methanol, ethanol,isopropanol, ethylene glycol, propylene glycol, actone, and methyl ethylketone. The colorant solutions may contain from about 30 ppm wt of dyeto about 1.0% by weight of dye with dye contents of 100 ppm to about0.5% being preferred and dye contents of 250 ppm to 0.2% being mostpreferred.

What is claimed is:
 1. A process for dyeing a proteinaceous fibersubstrate which comprises applying to said substrate a solution of afree amine-containing polymeric colorant comprising an aqueous solventof pH 2.0 to 4 inclusive in which is dissolved from 100 ppm to 0.5% byweight of a polymeric colorant having the structural formula ##STR83##wherein R₁ and R₁ ' independently are selected from hydrogen and lowersaturated alkyls of 1 to 4 carbon atoms; R₂ and R₂ ' independently areselected from hydrogen, lower saturated alkyls of 1 to 4 carbon atomsand phenyl; R₃ is selected from a simple carbon to nitrogen singlecovalent bond, 1 to 4 carbon atom lower saturated alkylene bridges, anda (phenylene) bridge; R₄ is selected from hydrogen and lower saturatedalkyls of 1 to 4 carbon atoms; R₅ is selected from a carbon to carbonsingle bond, ethylene, a 1 to 4 carbon saturated alkylsubstitutedethylene, a 6-8 carbon aromatic-substituted ethylene, a ##STR84##substituted ethylene wherein R₇ is selected from hydrogen 1 to 4 carbonalkyls, and --O--CH₃, an ##STR85## substituted ethylene, and anitro-substituted ethylene, Chrom is an optically chromophoric group andn, p, and m are numbers such that n is at least 1/2m and the sum ofn+m+p is such as to assure a molecular weight of at least 2000 to thecolorant molecule, and thereafter rinsing the substrate with water anddrying the substrate.